In the related art, treatments have generally been performed in which medical devices such as endoscopes and suction devices are introduced into a biological organ (for example, a body cavity such as an esophagus, airway, intestine, urinary duct, and other organs), and in which these devices are used so as to treat a lesion site appearing in the biological organ, or so as to perform removal of various foreign objects (capturing target) which are present inside the biological organ.
An example of the foreign object can include a calculus formed in the urinary tract. A urinary tract stone is the calculus, which is present in the urinary tract such as the kidney, the urinary duct, the bladder, and the urethra. In case of a urolithiasis, various symptoms are caused to occur due to the urinary tract stone. For example, when the calculus formed inside the kidney moves to the urinary duct, the urinary duct is injured by the calculus, thereby causing pain or hematuria. The calculus occludes the urinary duct, thereby bringing a patient into a transient hydronephrosis state. Consequently, the patient is forced to feel a severe pain (colicky pain) in a range from the waist back to the flank. To remove the calculus is effective means for relieving or treating the symptoms.
In order to remove the calculus, a method has been widely used in which the calculus is picked and extracted by using basket forceps (refer to JP-T-2001-512355). However, it can be necessary to pick the calculus one by one and to extract the calculus from a living body. Consequently, the method can be a very laborious task.
Here, for example, if a method of removing the calculus is tried in such a way that a filter for use in removing a foreign object inside the blood vessel is diverted for the purpose of efficiently extracting the calculus, and that the calculus is accommodated in an accommodation vessel having the filter attached thereto while the calculus aspirated by a fluid is collected in the filter, the above-described problem may be solved.
Furthermore, a size or an amount of the calculus varies depending on a patient. Accordingly, it is preferable to introduce a new technology for treating the patient by adjusting a size of a lumen in an accommodation vessel. However, even when the accommodation vessel is configured to be simply deformable, if unevenness occurs in the lumen of the accommodation vessel, a fluid is disturbed. If the fluid is hindered from flowing in the lumen, it is no longer possible to maintain a suction force required to capture a capturing target. Consequently, there is a possibility that the capturing target cannot be sufficiently captured.